Sprue-forming device



April 25, 1939. P. L. PERAZO SERUE-FORMING DEVICE Filed March 6, 1957 INVENTOR.

PETER LPERHZO BY ATTORNEY.

Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE 2,155,800 SPRUE-FORMING DEVICE Peter L.

Perazo, Oakland, Calif. Application March 6, 1937, serial 3 Claims. (C1. 22 ss sand about a pattern. An object of the invention is to provide an im- An added object is to provide an i and squeeze board combination.

The invention possesses other objects and features of advantage, some of which, with the foreproved flask Figure 2 is an enlarged axial section of a sprue punch assem y of Figure 1, the view being taken at 2-2 in Figure 1.

Figure 3 is a fragmentary and partly sectional view showing a sprue punch assembly of Figure 1 having its punch engaging the pattern in the flask.

By way of illustration, the features of present invention for castings to be produced therein or in an undera lying flask section.

Openings l3 are provided transversely through .the squeezer oard 5, and basin pattern members Like punches difierent openings Is for forming opening while the member I5 is more or less oval in plan It will beunderstood that the member I5, shapes a pouring basin I for the passage provided by its punch, while the 2 member l4 shapes a funnel-like'upper end for k or as an air vent for for convenience, both of said passages are hereinafter referred to as sprues. 25

externally tapered whereby the punch may wedg- 30 the bore I8 as the punch is pushed downwardly 40 .the latter may also, on occasion, be referred to as member 22 having its central opening aligned justed positioning of the punch and spring assemaffecting the use of the punches l1 adjusted in sired for providing its required pattern.

force the board 5 into the bly as a unit with respect to the board, and while the punch is engaged in the sand of a mold.

The punch I1 and its associated spring 2| are also preferably engaged for relative adjustment longitudinally thereof. Accordingly, and as shown, the exterior of the upper punch portion may be formed with a spiral thread groove having the pitch of the lower coils of the spring 21 and arranged to threadedly receive said coils whereby the punch is adjustably mounted within the lower spring portion. As illustrated, the lower spring portion which receives the upper punch portion is of reduced diameter number of spring coils may be constantly free of the punch; in this manner, the operative length. of the spring is not changed when the punch is adjusted with respect to the spring.

It will now be noted that the squeezer board 5 is shaped and adapted to slidably fit within the between the walls 21 of the flask section 1 inthe general manner of a piston, and

is provided with cleats 28 which extend abovethe punch-carrying brackets 23 whereby the upper press plate (not shown) of a usual press may engage across the cleats for-forcing the punch assembly on the board into the sand of the section I while compacting the sand beneath the board; as an alternative, the cleats 28 might. be free. or be mounted on the press plate without pressor the operation of the squeeze board 5.

At and around the periphery of its sand-engaging face, the squeezer board 5 is preferably provided with a protru ing flange or rim 29 having its exposed face more or less rounded; as shown, the flange 29 comprises half-round molding. The flange 29 is operative to prevent a lateral movement of the sand from beneath the board as the latter is pressed against the sand.

For providing connected sprue and mold openings in the present flask in connection with the pattern 8 on the plate 9, the distances fromthe top flask plane to the points of the pattern 8 which are to be disposed in the lines of the are measured, and the punches are their described mountings onthe squeezer board 5 to extend for slightly greater distances from the top plane ofthe board than said measured distances. Since patterns in the flask may vary somewhat in depth as measured from the plate 9, both described devices for adjusting the spacing of the advance end-of a punch with respect to the a jointly utilized for disposing the punch end as decontact with the Having the punch, or punches, adjusted as required, and'the molding sand placed in unpacked condition in the flask section around and above the pattern to the approximate level of the upper flask plane, the squeezer board is now deposited vertically upon the sand in the flask for effecting the entry of the punches l1 into the sand while aligning the board with the bore of the flask. A subsequent engagement of the assembly between the upper and lower thrust plates of a press, and the operation of the press may upper end of the flask section to compress thesand while forcing the punches therethrough for engagement with the pattern, the compressive movement of the board being stopped, in the present instance, when the outer board face is flush with the top flask plane.

whereby the same waste It will now be particularly noted that a punch l'l engaging a pattern in the flask has been thereby forced inwardly against the resistance of its spring 2| whereby it resiliently engages the pattern with its bottom edge preferably engaging flat against an upper pattern face thereat with a pressure which varies with its imposed inward movement with respect to the board 5. Since the punch is positively restrained against lateral displacement only at the point where it may engage the side of an opening H3 in a basin patl5, some displacement of the punch the line of its normal position is V V is advanced toward the pattern, this being desirable to overcome any unbalanced resistance which the punch may-encounter as it is being pushed toward the pattern, whereby: to minimize the effect .of friction and to insure the flat and sealed engagement of the punch end with the pattern surface engaged by it. If the pressure bearing of an installed p patternis not as required or desired, adjustment may be made while the boardis in place by suitable manipulation of the adjustment bolts 26.

When the sprue and mold spaces have been formed by the punches and patterns, a vertically upright removal of thesqueeze board and the elements thereon may be effected, and a subsepermits a gravity After thepattern 8 has been removed from the under side of the flask section, the latter may then be combined with, a previously prepared lower flask section (not shown) forcompleting the mold space for use in casting in a usual way.

From the foregoing description taken in connection with the accompanying drawing, the-advantages of the construction and method of use will be readily understood by those skilled in the art to which this invention appertains. While I have described the features andprinciples of operation of a structure which I now consider to be a preferred embodiment of my invention, I desire to have it understood that the present showingis primarily illustrative, and that such changesmay be made, when desired, as fall within the ,scope of the following claims.

I claim:

1. In combination with a squeeze boardfor. a molding flask, an helical compression spring, a sprue punch threadedly engaged with the coils of an endportion of the spring axially thereof for its axial adjustment with respect to the engaged spring portion to adjustably vary the distance of the punch point from the extremity of the engaged spring portion, and means unitarily attaching the other spring end tothe board to dispose the spring in perpendicular relation thereto.

PETER L. PERAZO.

the extending sprue portion is 

